U.S. Pat. No. 7,339,484 describes an event-driven discovery method and apparatus in which a common event, e.g. a handshake with another person, associated with a first device preparing to communicate with a second device is detected. The first device discovers the second device in response to detection of the common event. During discovery, the first and the second device exchange information and optionally may establish a communication session to exchange further information if desired. A drawback of the described method is that a user is unable to control with which other persons he wants to share certain data.